Message Properties

A message can also include optional header fields, called properties,
specified as property name and property value pairs. Properties allow clients
and providers to extend the message header and can contain any information
that the client or the JMS provider finds useful to identify and process a
message. Message properties allow a consuming client to ask that only those
messages be delivered which fit a given criteria. For instance, a consuming
client might indicate an interest for payroll messages concerning part-time
employees located in New Jersey. The JMS provider will not deliver messages
that do not meet the specified criteria.

The JMS specification defines nine standard properties. Some of these
are set by the client and some by the JMS provider. Their names begin with
the reserved characters “JMSX.” The client or the JMS provider
can use these properties to determine who sent a message, the identity of
the application sending a message, the state of the message, how often and
when it was delivered, tansaction identification, and so forth. These properties
are useful to the JMS provider in routing messages and in providing diagnostic
information.